BOOL CreateRectRgn( int x1, int y1, int x2, int y2 );
x1
Specifies the x-coordinate of the upper-left corner of the region.
y1
Specifies the y-coordinate of the upper-left corner of the region.
x2
Specifies the x-coordinate of the lower-right corner of the region.
y2
Specifies the y-coordinate of the lower-right corner of the region.
Creates a rectangular region that is stored in the CRgn object.
TRUE if the operation succeeded; otherwise FALSE.
CRgn::CreateRectRgnIndirect, CRgn::CreateRoundRectRgn, ::CreateRectRgn